29. Identify the most important types of interparticle forces present in the solids of each of the following substances. a. Ar e. CH_(4) b. HCl f. CO c. HF g. NaNO_(3) d. CaCl_(2)

a. Ar: The most important type of interparticle force present in solid argon (Ar) is the van der Waals force (also known as London dispersion force). These forces arise due to temporary fluctuations in electron density within the atoms, leading to temporary dipoles that induce dipoles in neighboring atoms.<br /><br />b. HCl: The most important type of interparticle force present in solid hydrogen chloride (HCl) is the dipole-dipole interaction. HCl molecules are polar, with a positive hydrogen atom and a negative chlorine atom. The dipole-dipole interaction occurs between the positive end of one HCl molecule and the negative end of another HCl molecule.<br /><br />c. HF: The most important type of interparticle force present in solid hydrogen fluoride (HF) is the hydrogen bonding. Hydrogen bonding is a special type of dipole-dipole interaction that occurs when a hydrogen atom is bonded to a highly electronegative atom (such as fluorine in HF) and is attracted to a lone pair of electrons on another electronegative atom.<br /><br />d. CaCl2: The most important type of interparticle force present in solid calcium chloride (CaCl2) is the ionic bonding. Calcium chloride is an ionic compound, consisting of positively charged calcium ions (Ca2+) and negatively charged chloride ions (Cl-). The strong electrostatic attraction between the oppositely charged ions forms the ionic bond.<br /><br />e. CH4: The most important type of interparticle force present in solid methane (CH4) is the van der Waals force (also known as London dispersion force). Methane molecules are nonpolar, and the temporary fluctuations in electron density within the molecules lead to temporary dipoles that induce dipoles in neighboring molecules.<br /><br />f. CO: The most important type of interparticle force present in solid carbon monoxide (CO) is the dipole-dipole interaction. CO molecules are polar, with a positive carbon atom and a negative oxygen atom. The dipole-dipole interaction occurs between the positive end of one CO molecule and the negative end of another CO molecule.<br /><br />g. NaNO3: The most important type of interparticle force present in solid sodium nitrate (NaNO3) is the ionic bonding. Sodium nitrate is an ionic compound, consisting of positively charged sodium ions (Na+) and negatively charged nitrate ions (NO3-). The strong electrostatic attraction between the oppositely charged ions forms the ionic bond.